The move preceded the company's move into the cloud-based Unified Communications platform market, which was announced Tuesday morning. (See Genband Constructs Cloud-Based UC Service.)

Genband has said it will provide some comment on the fund-raising in the near future but suggests that the service launch was not reliant on the new cash injection. The SEC filing notes only that the funds are not intended for use in any merger and acquisition activity.

But there's a neat historical link to tease out here: Genband was backed heavily by one of its major shareholders, One Equity Partners, for the 2010 acquisition of Nortel's Carrier VoIP and Application Solutions (CVAS) business, which would have provided the bedrock for Genband's unified communications systems sector. (See Genband Wins Nortel's Carrier VoIP Biz.)

Rutberg revealed Genband's new round of funding in its monthly Wireless Industry Newsletter, which examines industry trends and lists wireless sector investments and M&A activity from the previous month. Not surprisingly, Genband lead the way in terms of new funding rounds, accounting for more than a third of the $867 million raised by 92 privately held companies.

The second-biggest wireless-related funding round of January, according to Rutberg's research, was raised by smart home thermostat developer Nest Labs, which banked $80 million.

— Ray Le Maistre, International Managing Editor, Light Reading